Process and device for the manufacture of textured yarns

ABSTRACT

An improvement relating to the environment of producing textured yarns, i.e., stretch or twist curled yarns, by a process involving the setting of a twist during cooling after heating of the yarn, the improvement relating to conducting such setting treatment of the moving yarn by making the yarn follow a lengthened distance comprising a winding or sinuous path between the heat treatment member and a subsequent deformation member i.e. a false twist spindle, to thereby cool the yarn. The device or apparatus necessary to effect such winding or sinuous path of the heated textured yarn comprises a plurality of return means so arranged that the yarn takes the course of at least one loop, preferably a double loop in its path from a heating member to a subsequent deformation member.

United States Patent [72] Inventor Henri Crouzet Chavonoz, France [21] Appl.No. 811,452

[22] Filed Mar. 28, 1969 [45] Patented [73] Assignee June 15, 1971 Moulinage Et Retorderie De Chavanoz [32] Priority Mar. 29, 1968 [33] France [3 l 49,839

[54] PROCESS AND DEVICE FOR THE MANUFACTURE HS, 77.3, 77.4,157, 157 TS, 106; 28/62, 71.3

[56] References Cited UNITED STATES PATENTS 2,863,280 12/1958 Ubbelohde 57/157 2,951,330 9/1960 Bouvet 57/34 3,112,600 12/1963 Stoddard et a1. 57/157 X 3,166,881 l/l965 Servage 57/34 OTHER REFERENCES German Printed Publication No. 1,199,433- Aug. 1965- Bruning Class 28, Subclass 62 Primary Examiner-- Donald E. Watkins Attorneys-Norman C, Armitage, H. William Petry and Luke .1. Wilburn, Jr.

ABSTRACT: An improvement relating to the environment of producing textured yarns, i.c., stretch or twist curled yarns. by a process involving the setting of a twist during cooling after heating of the yarn, the improvement relating to conducting such setting treatment of the moving yarn by making the yarn follow a lengthened distance comprising a winding or sinuous path between the heat treatment member and a subsequent deformation member i.e. a false twist spindle, to thereby cool the yarn. The device or apparatus necessary to effect such winding or sinuous path of the heated textured yarn comprises a plurality of return means so arranged that the yarn takes the course of at least one loop, preferably a double loop in its path from a heating member to a subsequent deformation member.

PATENTEDJUNISIBYI 3,584,450

mvm'mn HENRI CROUZET A'I'TUR N KY8 PROCESS AND DEVICE FOR THE MANUFACTURE OF TEXTURED YARNS The present invention relates to an improvement in a process for the manufacturing of textured yarns, e.g. stretch or twist curled yarns as well as an apparatus or device for carrying out such process; more particularly, the present invention relates to such process and apparatus wherein an improvement is provided whereby cooling and setting of a heated textured yarn is effected by making such yarn conform to a winding or sinuous path.

Many processes have been developed and subsequently utilized for the development of stretch yarns, such term designating a yarn which is generally formed of a plurality of thermoplastic continuous filaments obtained by twisting, setting the twist and subsequently untwisting.

At the present time, this type of yarn is generally prepared by a process which involves carrying out such steps in a single continuous operation, in particular by the application of a false twist. Thus, by the use of a false twist it is possible in accordance with the presently conducted processes to apply the above three phases or steps of twisting, setting and untwisting in a continuous operation.

In general practice, particularly when employing conventionally utilized synthetic yarns, the freezing" or setting of the twist is effected during cooling, which cooling is conducted after heating, cancelling the internal tensions imparted to the yarn by the overtwist. In this manner, the new helicoidal form given to the synthetic yarn is set or more accurately frozen during the cooling of the yarn prior to the untwisting below the false twist spindle. For this purpose, a certain distance covered by the yarn in free air is generally set between the false twist spindle and the outlet of the heating oven. As the heated yarn traverses this distance the twist imparted by the spindle backs up or winds up into the yarn.

While such a process is generally employed to produce these textured or stretch yarns it is unfortunate that in many cases the path of travel between the heating oven and subsequent deforrnation member, e.g., false twist spindle is insufficient so that the yarn becomes untwisted at a moment when it is still hot and plastic, which effect results in irregularities in the apparent volume of the treated yarn as well as differences in its physical properties, i.e., in the dyeing characteristics in particular. Accordingly, under such circumstances a process such as generally employed in the production of such yarns is unsatisfactory from the standpoint of providing a textured yarn of reproducible advantageous properties.

It is pointed out with regard to the above that the cooling of the yarn, particularly the synthetic yarn is particularly important on false twist texturing machines which rotate at a high speed, e.g., in the range of 100,000 turns/min. and even faster (up to 1,000,000 turns/min), particularly, in the case of high count yarns. Accordingly, in such environment the unsatisfactory nature of previously employed processes is particularly disadvantageous.

To remedy the disadvantages associated with conventionally employed processes it has been previously proposed to lengthen the trip or increase the distance that the yarn traverses between the heating oven and the deformation member, e.g., false twist spindle and/or to subject the yarn to the action of a flow of cold air, directed upon the yarn in the direction of the advance of the yarn or against such direction. Thus, for example, French Pat. No. 1,252,207, relates to such an improved system for the manufacturing of high count textile yarns. Thus, in accordance with the system disclosed in such French patent it is proposed to lengthen the distance covered by the yarn between the heating device and false twist spindle or to blow air on the yarn in such zone. Such previously proposed remedies, however, themselves suffer certain disadvantages. Thus, the lengthening of the course entails an increase in the height of the texturing machine which effects the upward motion or backing up of the twist; the use of artificial cooling complicates the construction of the machine and therefore requires additional expenditures of energy and money.

Alternatively, it has been proposed to lengthen the course of the yarn merely by increasing the distance between the heating oven and the false twist spindle. This solution per se, however, is not satisfactory because to obtain a yarn having a good elasticity, the tension in the heating oven must be low, this being favorable to the formation of a ballooning ahead of the spindle, which, among other effects, hinders the locking of the false twist and causes yarn breakage due to the now excessive centrifugal force. To remedy this disadvantage associated with this proposal it is necessary to either increase the tension ahead of the spindle, in the oven, or reduce the speed of the yarn. Neither of these two alternatives is satisfactory and, accordingly, this proposed remedy has not found practical significance.

Accordingly, it has long been a desire of the industry to provide a simple, yet efficient, means for overcoming the inherent deficiencies and disadvantages associated with conventional processes for the production of textured or stretch yarns in an environment comprising the three phases of twisting, setting, and untwisting of a synthetic yarn. This has now been accomplished in accordance with the process and apparatus of the present invention.

Thus, in accordance with the present invention it has been found that the aforementioned disadvantages and deficiencies of previously employed processes and apparatus can be overcome in a manner which consists in lengthening the distance covered by the yarn between the oven and the deformation member, i.e., false twist spindle by making the yarn run along a sinuous or winding path, particularly in the form of at least one loop.

Accordingly, it is a principle object of the present invention to provide such process and apparatus, wherein the inherent deficiencies and disadvantages of previously employed processes and apparatus are eliminated.

lt is yet a further object of the present invention to provide a simple and yet efficient means or system for eliminating the deficiencies of the prior art, such means relating to the manner in which the heated textured yarn travels between the heating oven and the deformation member in a system involving the twisting, setting and untwisting ofsynthetic yarns.

A still further object of the present invention comprises a process and apparatus by which the distance covered by the yarn between the heating oven and the deformation member is lengthened by making the yarn run along a sinuous or winding path, preferably in a form of at least one loop.

Still further objects and advantages of a novel process and apparatus of the present invention will become more apparent from the following more detailed description thereof.

The above objects and advantages of the process and apparatus of the present invention are obtained by providing a system wherein the distance covered by the heated textured yarn between the oven and deformation member, i.e., false twist spindle is lengthened by making the yarn run along a sinuous or winding path, particularly one in a form of at least one loop, and more particularly a double loop.

Advantageously, and in accordance with a preferred embodiment of the present invention, the tension of the yarn along the above described course varies slightly, due to a slight jamming effect, which effect only slightly breaks the backing up of the twist so that the yarn is in a relaxed state or condition in the heating oven and under a sufficient tension in the false twist spindle, with the resulting loss of twist being lower than that due to the friction in the heating oven. Such a feature of this preferred embodiment of the present invention therefore eliminates the disadvantage associated with previously employed processes wherein breakage of the yarn frequently occurred due to excesses forces applied thereto.

ln accordance with a still preferred embodiment of the process of the present invention the sinuous or winding path traveled by the yarn between the heating oven and a subsequent deformation member IS such that the yarn has the same direction at the entrance and the exit of the winding course but is set off or staggered so that the deformation member. i.e., false twlst spindle is removed from the axis of the heating oven. This provides the additional advantage of removing the spindle from direct line with the shaft effect of the oven, while avoiding the risk of contact of the false twist spindle with the fumes of the textile oil solutions within the oven. In accordance with this embodiment of the present invention, the sinuous or winding path taken by the yarn between the heating oven and subsequent deformation member will be in the form of an S-shaped double loop with parallel ends. Advantageously, such course is variable in length so that the distance traveled by the heated textured yarn can be varied or adjusted according to operating conditions, i.e., nature of the yarn, count, winding speed, etc. Thus, although the form of the path traveled by the heated textured yarn is preferably at least one loop, it is most preferably in the form of an S-shaped double loop as set forth above.

The process of the present invention is carried out through the employment of a device or apparatus as described below. Thus, in accordance with the present invention in order to allow the yarn to travel the sinuous or winding path between the heating element and subsequent deformation element, a plurality of yarn return means are employed between the exit ofthe yarn from the heating element and the entry of the yarn into a deformation clement, i.e., false twist means. As will be shown in the drawings it is preferred in accordance with the present invention that at least one of such return means be adjustable in its position so that the length or distance traveled by the yarn between the heating element and deformation member can be varied.

In accordance with an embodiment, these return means are composed of small wheels idly mounted on a fixed axle, or biconical fixed guides called diabolos" which permit the free upward motion or backing up ofthe false twist while maintaining a sufficient tension on the spindle to prevent the sliding of the twist on the locking means and a certain slack of the yarn in the heating box. This accordingly permits the obtaining of a maximum yarn elasticity in a manner not possible by previously employed apparatus and processes. Advantageously, in accordance with a preferred embodiment of the present invention the fixed guides described above have a groove in which the yarn passes, the diameter of the fixed guides being between about and mm. Preferably, they are made of a hard smooth material such as a sintered oxide, such material having a friction factor or coefficient of friction with respect to the yarn which is sufficient to allow for the characteristics described above.

In accordance with a still preferred embodiment of the present invention such return means are preferably combined with a heating box which is characterized by the fact that the same is pivotably mounted on a fixed axle and equipped with means to lock the heating box in a plurality of different positions. Such a novel heating box arrangement associated with the apparatus of the present invention is advantageous in that it permits the same machine or apparatus to operate either in direct course between the heating element and the false twist element or to conveniently lengthen said course by making the yarn follow a winding path by being out of alignment with the subsequent deformation member. This of course is of particular interest in high speed texturizing of high count yarns since it may be necessary to utilize both type of processes. In accordance with this embodiment of the present invention the heating box may be straight or curved, closed or open, a curved box being particularly preferred.

The process and apparatus of the present invention will now be described in connection with the accompanying FIGURE, which FIGURE diagrammatically illustrates the apparatus of the present invention and the manner in which the yarn is forced to follow a sinuous or winding path between the heating box and subsequent deformation member.

In accordance with the FIGURE, a yarn 1 goes through a heating element composed of a curved pipe 2 of small caliber which is directly heated by an electric resistance such as described in French Pat. No. l,l40,992, showing a curvature of 2 centimeters for a total length of 1 meter. For better understanding of the diagram, the yarn I has purposely been removed from the wall of the pipe.

Pipe 2 is placed inside of a heating box 6 which is rotatively mounted around a pivot 7, offset with respect to the axis ofthe passage of the yarn l in the false twist spindle 8. At the exit of the heating box 6, the yarn passes over fixed biconical guides 3, 4 and 5. Guide 5 is preferably adjustable in its position, for example at 5', thus permitting varying of the length of the loop according to the operating conditions such as winding speed, titre of the yarn, etc.

It is thus possible, either to lead the yarn 1 directly in the axis of the false twist spindle 8 (dotted lines: position 6' of the box), or to slightly tilt the box 6 and to form a long loop by passing the yarn over return members 3, 4 and 5,

The fixed box is locked into any of the positions indicated by any known means (not shown).

According to a further variation of the invention, rollers 3 and 4 also have adjustable positions.

After guide 5, the yarn passes in a false twist spindle 8 before it is taken up by a winding device (not shown).

Return members 3, 4 and 5 are either small wheels idly mounted on fixed axles, or biconical fixed guides, currently called diabolos"; the latter insure a minimum loss of twist, as long as they have optimum size, advantageously between about 10 and 20 mm. They are preferably made of any hard and smooth material, such as sintered oxides.

The process and apparatus of the present invention can be illustrated by the following example.

With the apparatus illustrated in the accompanying FIGURE, a denier (78 dtex)/23 filaments polyhexamethylene adipamide yarn is subjected was a false twist treatment under the following conditions:

speed of spindle: 400,000 turns/min.

twist: 3 I20 turns/min.

Temperature ofoven: 230 C. The yarn passed through the oven without any shrinkage or drawing.

As a comparison, an identical yarn was treated under the same conditions, but without cooling, i.e., passing directly and with a rate of drawing of2 percent in the oven.

The following results were obtained:

It is seen further above that the loss of strength is the same in both cases. It is equal to the loss of strength due to the false twist treatment, i.e., substantially 24 percent, the initial yarn having a breaking strength 0f5.6 g./den.

On the other hand, it is noted that the elasticity has increased substantially in accordance with the present invention and that the yarn may be heat treated with a lesser elongation without drawing. The result is that since the yarn is subjected to practically zero tension in the oven, the loss of twist is negligible, in the order of 50 turns/m., i.e., lower, at such speeds, than the loss of twist clue to friction in the heating element. However, the friction on the return means is sufficient to insure a proper locking of the twist of the yarn on the twisting member, while permitting a low tension, nearly negligible, upon contact with the heating'element.

This effect is even more noticeable we're the yarn is less elastic. It is particularly important at high speeds which normally require a certain tension of the yarn. Thus it is possible, with a I50 denier (I67 dtex)/30 filaments polyethylene terephtalate yarn, to treat this yarn according to the process of the present invention, with winding speeds higher then I00 m./min., with a shrinkage of approximately 4 percent in the oven. n the other hand, according to conventional processes, the yarn must be treated without shrinkage, or with a slight drawing.

Moreover, the knitted fabric made from a yarn according to the present invention shows a texture regularity comparable to that which can usually be obtained only through a setting treatment of the yarn itself with steam, Le, a slower discontinuous treatment which requires more manipulation and is therefore more expensive.

In addition, the process of the present invention is easy to apply with only minimum transformations in the equipment, and it permits a ,wide range of adjustments which are extremely simple to make.

What I claim is:

1. Apparatus for false twisting a running length of thermoplastic yarn comprising means for directing yarn in a desired path of travel, said means including false twisting means positioned in the yarn path upstream of the false twisting means for heating the twisted yarn passing to said false twisting means, and guide means positioned in the yarn path between the false twisting means and the heating means for directing the yarn in a sinuous path to permit cooling of the yarn between the heating means and false twisting means while permitting substantially unrestricted passage of the twist imposed on the yarn from the false twisting means into the heating means.

2. Apparatus as defined in claim 1 wherein said heating means includes a yarn outlet and adjustable means for varying the position of the outlet into and out of substantial alignment with said false twisting means to selectively bypass said guide means and shorten the path of travel of the yarn from the heating means to the false twisting means.

3. Apparatus as defined in claim 2 wherein said heating means includes an elongated heating member through which said yarn passes, and said adjustable means includes means for varying the angular position of said member to vary the position of the outlet end of said member into and out of substantial alignment with said false twisting means.

4. Apparatus as defined in claim 3 wherein said false twisting means includes a false twist spindle, said heating member is normally positioned upstream and to one side of said false twist spindle, said guide means are positioned generally upstream said false twist spindle and beside said heating member, and said heating member outlet is selectively positionable to be moved into axial alignment with said false twist spindle to thereby permit direct passage of running yarn to said spindle therefrom.

5. Apparatus as defined in claim 4 wherein said heating member comprises a curved heater tube through which the yarn being heated passes.

6. Apparatus as defined in claim 1 wherein said guide means includes a plurality of spaced guides for supportably engaging the yarn, at least one of said guides being positionally adjustable to selectively lengthen or shorten the yarn path between said heating means and said false twisting means.

7. Apparatus for false twisting a running length of thermoplastic yarn comprising means for directing yarn in a desired path of travel, said means including false twisting means including a false twist spindle positioned in the path of travel for twisting the moving yarn, yarn heating means having a yarn outlet normally positioned below and generally to one side of said false twist spindle for heating the yarn passing to said false twisting means, guide means including a plurality of spaced yarn guides positioned generally below said false twist spindle for normally directing yarn from said yarn outlet to said spindle in a sinuous path to permit cooling of the yarn between the heating means and false twisting means, and means for selectively positioning the yarn outlet of said heating means in axial alignment with said false twist spindle to selectively bypass said guide means and shorten the path of travel of the yarn from the heating means to the false twisting means.

8. Apparatus as defined in claim 7 wherein said heating means includes a yarn heater tube, and said means for selectively positioning the yarn outlet of the heating means includes means for varying the angular position of said heating tube to vary the position of the yarn outlet thereof.

9. Apparatus as defined in claim -8 wherein said heating means further includes a heater box surrounding said heater tube, and said adjustable means includes means mounting said heater box and heater tube for pivotal movement about a lower comer portion of said box.

10. Apparatus as defined in claim 7 wherein said yarn guides are rotatable rollers.

11. Apparatus as defined in claim 7 wherein said yarn guides are biconical elements.

12. Apparatus as defined in claim 7 wherein said guides have a diameter of from about l0 to 20 mm.

13. Apparatus as defined in claim 7 wherein said yarn guides are positioned whereby the yarn is guided to travel in the same direction immediately upon leaving said heating means and immediately prior to entering said false twisting means.

14. Apparatus as defined in claim 7 wherein said guides are positioned to provide a sinuous yarn path in the form of a double loop.

15. In a process for texturizing a running length of thermoplastic yarn comprising the steps of sequentially passing the yarn through a heating zone, a cooling zone, and a false twisting zone; the improvement wherein the: yarn is passed through said cooling zone in a sinuous path while permitting substantially unrestricted passage of twist from said false twisting zone into said heating zone.

16. A process as defined in claim 15 wherein said sinuous path is selectively variable in length.

17. A process as defined in claim 15 including the step of reducing the tension in the yarn in the heating zone below that in the false twisting zone while processing the yarn.

m UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N 3, 584, 450 Dated June 15, 1971 Inventor(s) Henri Crouzet It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[- In Column 3, line 66, "type" should be --types--.

In Column 5, line 18, after "path" insert --for twisting the moving yarn, heating means positioned in the yarn path--.

Signed and sealed this 7th day of December 1 971 (SEAL) Attest:

EDWARD M.FLETCHER,JB. ROBERT GOTTSCHALK Acting Commissioner of Patents Attesting Ufiicer 

1. Apparatus for false twisting a running length of thermoplastic yarn comprising means for directing yarn in a desired path of travel, said means including false twisting means positioned in the yarn path upstream of the false twisting means for heating the twisted yarn passing to said false twisting means, and guide means positioned in the yarn path between the false twisting means and the heating means for directing the yarn in a sinuous path to permit cooling of the yarn between the heating means and false twisting means while permitting substantially unrestricted passage of the twist imposed on the yarn from the false twisting means into the heating means.
 2. Apparatus as defined in claim 1 wherein said heating means includes a yarn outlet and adjustable means for varying the position of the outlet into and out of substantial alignment with said false twisting means to selectively bypass said guide means and shorten the path of travel of the yarn from the heating means to the false twisting means.
 3. Apparatus as defined in claim 2 wherein saiD heating means includes an elongated heating member through which said yarn passes, and said adjustable means includes means for varying the angular position of said member to vary the position of the outlet end of said member into and out of substantial alignment with said false twisting means.
 4. Apparatus as defined in claim 3 wherein said false twisting means includes a false twist spindle, said heating member is normally positioned upstream and to one side of said false twist spindle, said guide means are positioned generally upstream said false twist spindle and beside said heating member, and said heating member outlet is selectively positionable to be moved into axial alignment with said false twist spindle to thereby permit direct passage of running yarn to said spindle therefrom.
 5. Apparatus as defined in claim 4 wherein said heating member comprises a curved heater tube through which the yarn being heated passes.
 6. Apparatus as defined in claim 1 wherein said guide means includes a plurality of spaced guides for supportably engaging the yarn, at least one of said guides being positionally adjustable to selectively lengthen or shorten the yarn path between said heating means and said false twisting means.
 7. Apparatus for false twisting a running length of thermoplastic yarn comprising means for directing yarn in a desired path of travel, said means including false twisting means including a false twist spindle positioned in the path of travel for twisting the moving yarn, yarn heating means having a yarn outlet normally positioned below and generally to one side of said false twist spindle for heating the yarn passing to said false twisting means, guide means including a plurality of spaced yarn guides positioned generally below said false twist spindle for normally directing yarn from said yarn outlet to said spindle in a sinuous path to permit cooling of the yarn between the heating means and false twisting means, and means for selectively positioning the yarn outlet of said heating means in axial alignment with said false twist spindle to selectively bypass said guide means and shorten the path of travel of the yarn from the heating means to the false twisting means.
 8. Apparatus as defined in claim 7 wherein said heating means includes a yarn heater tube, and said means for selectively positioning the yarn outlet of the heating means includes means for varying the angular position of said heating tube to vary the position of the yarn outlet thereof.
 9. Apparatus as defined in claim 8 wherein said heating means further includes a heater box surrounding said heater tube, and said adjustable means includes means mounting said heater box and heater tube for pivotal movement about a lower corner portion of said box.
 10. Apparatus as defined in claim 7 wherein said yarn guides are rotatable rollers.
 11. Apparatus as defined in claim 7 wherein said yarn guides are biconical elements.
 12. Apparatus as defined in claim 7 wherein said guides have a diameter of from about 10 to 20 mm.
 13. Apparatus as defined in claim 7 wherein said yarn guides are positioned whereby the yarn is guided to travel in the same direction immediately upon leaving said heating means and immediately prior to entering said false twisting means.
 14. Apparatus as defined in claim 7 wherein said guides are positioned to provide a sinuous yarn path in the form of a double loop.
 15. In a process for texturizing a running length of thermoplastic yarn comprising the steps of sequentially passing the yarn through a heating zone, a cooling zone, and a false twisting zone; the improvement wherein the yarn is passed through said cooling zone in a sinuous path while permitting substantially unrestricted passage of twist from said false twisting zone into said heating zone.
 16. A process as defined in claim 15 wherein said sinuous path is selectively variable in length.
 17. A process as defined in claim 15 including the step of reducing the tension in the yarN in the heating zone below that in the false twisting zone while processing the yarn. 